The present invention relates to flavoring of chewing gum. More particularly, the present invention describes methods and compositions for providing a long flavor duration in chewing gum.
Chewing gums typically contain many ingredients including flavor ingredients, sweetener ingredients and flavor-enhancing ingredients. It is often desirable to produce a chewing gum having a high degree of sweetness and flavor, which lasts for an extended period of time. xe2x80x9cFast releasexe2x80x9d chewing gums known in the art typically release their flavor and sweetness compounds rapidly, creating an initial burst of high intensity sweetness and flavor which is pleasing to the consumer but which does not last. Conversely, xe2x80x9cslow-releasexe2x80x9d chewing gums release their sweetness and flavor over a longer period of time but do not provide an initial burst of high intensity sweetness and flavor. Hence, chewing gum manufacturers are constantly trying to extend the time in which consumers can enjoy the sweetness and flavor of chewing gum without sacrificing the quality of the initial sweetness and flavor impact.
Various methods and compositions have been described for providing better control of the release of flavoring agents and increasing the length of flavor duration. For example the art describes the encapsulation of flavoring agents and other active ingredients into matrices. Examples of such matrices are disclosed in, for example, U.S. Pat. Nos. 4,978,537; 2,290,120; 2,596,852; 3,085,048; 3,795,744; 3,826,847; 3,818,107; 3,962,463; 4,217,368; 4,259,355; 3,962,463; 4,217,368; 4,259,355; 4,230,687; 4,590,075 and 5,128,155 and PCT Patent Publication No. WO 98/27826 (each of which is incorporated herein by reference). These patents are discussed in further detail herein below.
U.S. Pat. No. 4,978,537 discloses gradual release structures formed by meltspinning a mixture of an active agent and a wall material. U.S. Pat. No. 2,290,120, discloses the mixing of particles of chewing gum base with the flavoring agent to provide a substantially homogeneous mixture.
U.S. Pat. No. 2,596,852 discloses chemically reacting the chewing gum base with molecules of flavor ingredient, wherein the chewing gum base is a vinyl acetate polymer and the flavor molecule contains an ethylenic bond. U.S. Pat. No. 2,886,446, discloses the coacervation of a typically volatile, water immiscible flavoring oil within a body of gelatin. U.S. Pat. No. 3,085,048 discloses a process for coating dicalcium phosphate with sugar. U.S. Pat. Nos. 3,795,744, and 3,826,847 disclose the coating, encapsulation or combination of flavoring agents with high molecular weight compounds including starches, cellulose, proteins, gums, polyvinyl alcohol and polyvinyl esters. U.S. Pat. No. 3,818,107, discloses flavoring agent appended to a polymer backbone, releasable upon hydrolysis.
U.S. Pat. No. 3,962,463 discloses the encapsulation of flavor ingredients in gelatin waxes, polyethylene and the like followed by the depositing of the encapsulated flavor particles on the surface of the chewing gum. U.S. Pat. No. 4,217,368 discloses the controlled release of a (second) sweetener which is dispersed in, enveloped by, trapped in and otherwise protected by the gum base. A first sweetener, which is relatively unprotected, provides an initial burst of flavor. U.S. Pat. No. 4,259,355 discloses a hydrolytically releasable flavor oil entrapped in gelatine, dextrin, gum acacia or modified food starch with the aid of a hydroxypropylcellulose solid suspending agent. A hydrophobic unconfined flavor oil provides an initial burst of flavor.
U.S. Pat. No. 4,230,687 discloses the encapsulation of flavoring agent in a polymeric medium using rigorous and intimate conditions of mechanical shear to mix the flavoring agent with the encapsulating medium. The flavoring agent is gradually released from the encapsulating matrix at a rate dependent upon the rate of hydration of the matrix, which in turn depends upon the particular matrix used. The polymeric matrix may be derived from natural substances such as casein, a gelatin, modified starches, gums and related materials.
U.S. Pat. No. 4,590,075 discloses a flavor and sweetener delivery system including a flavoring agent and/or sweetener encapsulated in an elastomeric matrix. The elastomeric matrix is substantially hydrophobic and includes an elastomer, an elastomer solvent, a wax system and an excipient. The excipient, which is present only in small amounts, can include carbohydrate materials (including partially hydrolyzed starch), polyhydric alcohols, and mixtures of carbohydrates and polyhydric alcohols.
Despite this substantial body of work, there remains a deficiency in the art in that the duration and intensity of flavor can not be sustained for long periods of time. A matrix material that has attracted interest for its ability to improve flavor characteristics of gum is hydroxypropylcellulose (hereinafter referred to as HPC). U.S. Pat. No. 5,128,155 (specifically incorporated herein by reference) describes HPC compositions with silica and plasticizers as flavor cores for chewing gum. In these compositions, the silica was thought to be necessary and sufficient to act as a flavor reservoir material. PCT Publication WO 98/27826 suggests that low levels of HPC may be useful in increasing the amount of flavor released from chewing gum. For these compositions to be useful it was necessary to incorporate the HPC directly into the gum composition, as opposed to being premixed with another ingredient or used as an encapsulant or agglomeration agent. Furthermore, the HPC had to be present in concentrations of less than 1% if the gum integrity was to be maintained.
Clearly, the prior art demonstrates that there is a need for increasing the flavor duration and intensity in chewing gum compositions. While this need has been partly met, further improvements would be a great benefit. The present invention is directed toward methods and compositions overcome this deficiency in the prior art.
There is a need in the art to improve the flavor duration and/or intensity of chewing gum. The present invention is directed towards addressing this need. The present invention provides methods and compositions that improve the duration of flavor in chewing gum without compromising the integrity of said gum or flavor. This beneficial outcome is preferably achieved by using novel high molecular weight HPC matrices.
In particular, the present invention provide a method of making a long flavor duration releasing structure for chewing gum comprising mixing a cellulose material having hydroxyl groups thereon with a multi-functional carboxylate to form a generally homogeneous composition; treating the composition to a curing temperature for a sufficient amount of time to form a matrix having a low water solubility; sizing the matrix to a size to be used in chewing gum compositions; and incorporating flavoring agents into the matrix.
Other aspects of the present invention provides a long flavor duration releasing structure comprising a cellulose material with hydroxyl groups thereon mixed with a cross-linking agent and cured to form a matrix having a low water solubility, and a flavoring agent incorporated into the matrix.
Also contemplated herein is a chewing gum composition with long flavor duration comprising a gum base; a water soluble bulk portion; and a flavor releasing structure comprising:
i) a matrix formed by mixing an aqueous solution containing hydroxypropylcellulose with an aqueous solution containing a cross-linking agent and evaporating water from the mixture; and
ii) a flavor agent incorporated into the matrix.
Yet another aspect of the present invention provides a method of making a chewing gum composition with a long flavor duration comprising the steps of mixing a cellulose material having hydroxyl groups thereon with water until the cellulose material is hydrated; drying the water from the cellulose material; curing the cellulose material for a time period of at least 4 hours and at a temperature of at least 120xc2x0 C. to form a matrix having a lower water solubility than the original cellulosic material; sizing the matrix to a size useful as an ingredient in chewing gum; incorporating flavor into the matrix; and mixing the matrix with flavor incorporated therein with a gum base and a bulking agent to form the chewing gum composition.
Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.